U.S. patent application number 15/968820 was filed with the patent office on 2018-09-06 for display device.
The applicant listed for this patent is Japan Display Inc.. Invention is credited to Hsiang Yuan CHENG.
Application Number | 20180252959 15/968820 |
Document ID | / |
Family ID | 59680300 |
Filed Date | 2018-09-06 |
United States Patent
Application |
20180252959 |
Kind Code |
A1 |
CHENG; Hsiang Yuan |
September 6, 2018 |
DISPLAY DEVICE
Abstract
In a display device using a substrate having flexibility, a drop
in reliability due to defects such as cracks in the case where a
substrate is made to curve is controlled. A display device is
provided including a first substrate having flexibility, the first
substrate including a curved part, an organic film covering a first
surface of the first substrate and a second surface opposing the
first surface in the curved part; and a pixel part and a drive
circuit part arranged on the first surface.
Inventors: |
CHENG; Hsiang Yuan; (Tokyo,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Japan Display Inc. |
Tokyo |
|
JP |
|
|
Family ID: |
59680300 |
Appl. No.: |
15/968820 |
Filed: |
May 2, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15296111 |
Oct 18, 2016 |
9989791 |
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15968820 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02F 1/136286 20130101;
Y02E 10/549 20130101; H01L 51/5253 20130101; G02F 1/133305
20130101; H01L 51/0097 20130101 |
International
Class: |
G02F 1/1333 20060101
G02F001/1333; H01L 51/52 20060101 H01L051/52; H01L 51/00 20060101
H01L051/00; G02F 1/1362 20060101 G02F001/1362 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 25, 2016 |
JP |
2016-034269 |
Claims
1. A display device comprising: a first substrate having
flexibility, the first substrate including an upper surface and a
side surface intersecting the upper surface; a pixel part on the
upper surface of the first substrate; and a sealing member entirely
covering the pixel part, the sealing member including an upper
surface and a side surface intersecting the upper surface, wherein
the first substrate includes a curved part adjacent to the pixel
part, an organic film covers the upper surface of the first
substrate at the curved part, the organic film is in contact with
the side surface of the sealing member, and the organic film is not
in contact with the upper surface of the sealing member.
2. The display device according to claim 1, wherein the organic
film further covers the side surface of the first substrate at the
curved part.
3. The display device according to claim 2, wherein the organic
film covers the upper surface of the first substrate and the side
surface of the first substrate continuously.
4. The display device according to claim 1, wherein a thickness of
the organic film is smaller than that of the sealing member.
5. The display device according to claim 1, wherein The sealing
member doesn't cover the curved part.
6. The display device according to claim 1, further comprises a
wiring part on the upper surface of the first substrate, the wiring
part connected to the pixel part, and extending from the pixel part
to the curved part, wherein a part of the wiring part is covered
with the sealing member, another part of the wiring part is exposed
from the sealing member, and the exposed part of the wiring part is
located on the curved part.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from the prior Japanese Patent Application No.
2016-034269, filed on Feb. 25, 2016, the entire contents of which
are incorporated herein by reference.
FIELD
[0002] One embodiment of the present invention is related to a
substrate structure of a display device having flexibility.
BACKGROUND
[0003] A display device is disclosed in which an electroluminescent
element or liquid crystal element is used as a display element and
a circuit for driving the display element is formed using a thin
film transistor. One form of a display device is disclosed in which
it is possible to bend and curve using a substrate having
flexibility (for example, Japanese Laid Open Patent Publication No.
2015-169711).
[0004] A display device includes a circuit element such as a thin
film transistor or capacitor element and the like above a
substrate, and a wiring part connecting the circuit element. In
addition, an organic insulation film and inorganic insulation film
buried between these layers or an organic insulation film arranged
above each electrode for example is arranged on roughly the entire
surface of a substrate. Here, when a substrate having flexibility
is curved, stress is applied to a thin film arranged above the
substrate and defects such as cracks and the like are produced
which is a problem. That is, even if a substrate has flexibility,
since a thin film such as an inorganic insulation film and the like
arranged thereupon does not always include the same flexibility,
defects such as cracks and the like are produced in the thin film
when the flexible substrate is bent. For example, when defects such
as cracks and the like are produced in an inorganic insulation film
above a flexible substrate, water infiltrates from the defects and
causes degradation of a display element in a pixel region.
SUMMARY
[0005] According to one embodiment of the present invention, a
display device is provided including a first substrate having
flexibility, the first substrate including a curved part, an
organic film covering a first surface of the first substrate and a
second surface opposing the first surface in the curved part; and a
pixel part and a drive circuit part arranged on the first
surface.
BRIEF DESCRIPTION OF DRAWINGS
[0006] FIG. 1 is a planar view diagram showing a structure of a
display device related to the present embodiment;
[0007] FIG. 2 is a cross-sectional diagram showing a structure of a
display device related to the present embodiment and shows a
structure along the line A-B shown in FIG. 1;
[0008] FIG. 3 is a cross-sectional diagram showing a structure of a
display device related to the present embodiment and shows a
structure along the line C-D shown in FIG. 1;
[0009] FIG. 4 is a cross-sectional diagram showing a structure of a
display device related to the present embodiment and shows a state
where a substrate is curved in the structure along the line A-B
shown in FIG. 1;
[0010] FIG. 5 is a cross-sectional diagram showing a structure of a
display device related to the present embodiment and shows a state
where a substrate is curved in the structure along the line A-B
shown in FIG. 1; and
[0011] FIG. 6 is a cross-sectional diagram showing a structure of a
display device related to the present embodiment and shows a
structure along the line C-D shown in FIG. 1.
DESCRIPTION OF EMBODIMENTS
[0012] One aim of an embodiment of the present invention is to
control a drop in reliability due to defects such as cracks and the
like even in the case where a substrate is curved in a display
device using a substrate having flexibility.
[0013] The embodiments of the present invention are explained below
while referring to the diagrams. However, it is possible to perform
the present invention using various different forms, and the
present invention should not be limited to the content described in
the embodiments exemplified herein. Although the width, thickness
and shape of each component are shown schematically compared to
their actual form in order to better clarify explanation, the
drawings are merely an example and should not limit an
interpretation of the present invention. In addition, in the
specification and each drawing, the same reference symbols are
attached to similar elements and elements that have been mentioned
in previous drawings, and therefore a detailed explanation may be
omitted where appropriate.
[0014] In the present specification, in the case where certain
parts or regions are given as [above (or below)] other parts or
regions, as long as there is no particular limitation, these
include parts which are not only directly above (or directly below)
other parts or regions but also in an upper direction (or lower
direction). That is, in the case where certain parts or regions are
given as [above (or below)] other parts or regions, other
structural elements may be included between other parts or regions
in an upper direction (or lower direction).
[0015] FIG. 1 shows a structure of a display device 100 related to
one embodiment of the present invention. In addition, in the
display device 100 shown in FIG. 1, a cross-sectional structure
along the line A-B is shown in FIG. 2 and a cross-sectional
structure along the line C-D is shown in FIG. 3. These diagrams are
referred to in the explanation below.
[0016] The display device 100 includes a pixel part 104 arranged
with a pixel 106 in a first surface 10 of a first substrate 102.
The display device 100 includes a drive circuit part for driving
the pixel 106 in a region (periphery region) on the exterior of the
pixel 104 in the first substrate 102. The drive circuit includes a
first drive circuit 108 which outputs a scanning signal and a
second drive circuit 110 which outputs a video signal synchronized
with the scanning signal. The second drive circuit 110 is a driver
IC for example mounted above the first substrate 102. In addition,
a terminal part 112 which is input with signals is arranged in a
region on the exterior side of the first substrate 102. The
terminal part 112 includes a terminal which is input with a video
signal. The terminal part 112 is electrically connected to a wiring
substrate 118. The driver IC described above, that is, the second
driver circuit 110, may be mounted above the wiring substrate
118.
[0017] The first drive circuit 108, the second drive circuit 110
and the pixel part 104 are connected via wiring. This connection
region includes wiring formed from a conductive film and an
insulation layer buried with this wiring. In the present
specification, this connection region in a region between a pixel
part and a drive circuit part is referred to as a wiring part. The
display device 100 includes a first wiring part 114 between the
pixel part 104 and the first drive circuit 108, and a second wiring
part 116 between the pixel part 104 and the second drive circuit
110.
[0018] In the present embodiment, the first substrate 102 includes
flexibility. A resin material is used for the first substrate 102
which includes flexibility. It is preferred that a high molecular
material including recurring units of imide bonds is used as the
resin material, polyimide for example. Specifically, a film
substrate with polyimide molded into a sheet shape may be used as
the first substrate 102. In addition, as another form of the first
substrate 102, it is possible to use a thin metal substrate, a
compound substrate in which a resin film is bonded to a thin metal
substrate, or a compound substrate in which a resin film is bonded
to a thin glass substrate.
[0019] The display device 100 is arranged with a sealing member 126
opposing the first substrate 102. The sealing member 126 is also
referred to as a second substrate opposing the first substrate 102.
The pixel part 104 is covered by the sealing member 126. The
sealing member 126 is formed from a cover film using a resin
material or a sheet shaped component.
[0020] At least one part of the display device 100 includes a
curved part 120. That is, by providing the first substrate 102 with
flexibility, it is possible to provide a bent state to at least a
part of the display device 100. The curved part 120 is a region in
which the first substrate 102 bends or curves. When the first
substrate 102 curves, parts which overlap with at least the curved
part 120 within the pixel part, the drive circuit part and wiring
part also curve together with the first substrate 102.
[0021] The display device 100 is arranged with a support member 122
in a second surface 20 opposing the first surface 10 of the first
substrate 102. Although the support member 122 is arranged so as to
cover roughly the entire surface of the first substrate 102, a
notch part 124 is also included in at least a part of the support
member 122. The support member 122 which is arranged close to the
first substrate 102 essentially operates in the same way as
increasing the thickness of a substrate. That is, the support
member 122 controls bending of the first substrate 102. On the
other hand, since the thickness of the first substrate 102 is
maintained by the notch part 124 of the support member 122, the
first substrate 102 may easily bend compared to regions where the
support member 122 is arranged. A region of the first substrate 102
corresponding to the notch part 124 of the support member 122
becomes the curved part 120.
[0022] The support member 122 is formed from the same resin
material as the first substrate 102 or a component which is harder
than the first substrate 102. A resin substrate formed from a
silicon resin and the like or a substrate such as an acrylic plate
may be used as the support member 122. Furthermore, in the present
embodiment, the support member 122 is not an essential structural
component but a structural component which can be used
appropriately. However, as described above, by using the support
member 122, bending of the first substrate 102 is controlled, and
by arranging the notch part 124, it is possible to set the position
of the curved part 120 of the display device 100.
[0023] The notch part 124 of the support member 122 can be arranged
at an arbitrary position and an arbitrary width. FIG. 2 shows a
form in which the notch part 124 of the display device 100 is
arranged between the pixel part 104 and second drive circuit 110.
In other words, a region which overlaps with the second wiring part
116 of the display device 100 shown in FIG. 2 becomes the curved
part 120.
[0024] As is shown in FIG. 2 and FIG. 3, the display device 100
includes an organic film 128 in a region including the curved part
120. The organic film 128 is arranged so as to cover an upper
surface of the second wiring part 116 in the first surface of the
first substrate 102. In other words, the organic film 128 is
arranged in a region between the pixel part 104 and the second
drive circuit part 110. The second wiring part 116 is covered and
protected by the organic film 128. The organic film 128 is also
arranged on the side of the second surface 20 of the first
substrate 102. In addition, the organic film 128 is arranged to
cover a region between the first surface 10 and second surface 20
of the first substrate 102, that is, to cover a side surface part
of the first substrate 102. By arranging the organic film 128 in
the first substrate 102 in this way, it is possible to use the
organic film 128 as a protection film of the curved part 120. For
example, even in the case where stress is concentrated on one part
of the curved part 120 and defects such as cracks occur in the
second wiring part 116, by arranging the organic film 128
continuously in the first surface 10 and second surface 20 of the
first substrate 102, it is possible to ensure that defects are not
exposed to the air.
[0025] FIG. 4 shows a state of the display device 100 when the
first substrate 102 is made to curve in the curved part 120. The
first substrate 102 curves so that the second drive circuit 110 is
arranged on the rear surface side of the pixel part 104. Bending
stress is applied to the curved part 120 of the first substrate
102. For example, bending stress is applied to the second wiring
part 116 when the first substrate 102 is bent. That is, bending
stress is applied to wiring included in the second wiring part 116
and an insulation layer buried with this wiring. In this case,
although a metal film which forms the wiring is resistant to
bending due to flexibility, defects such as cracks occur since at
least an inorganic insulation layer among the insulation layers
buried with the wiring is brittle. Defects such as cracks occurring
in the second wiring part 116 proceed (grow) towards the pixel part
104. Supposing that defects such as cracks in the second wiring
part 116 are exposed to the air, water and the like infiltrates to
the pixel part 104 from the cracks which affects reliability of the
display device 100.
[0026] The display device 100 related to the present embodiment is
arranged with the organic film 128 covering the second wiring part
116. As is shown in FIG. 3 and FIG. 4, the organic film 128 is not
arranged in the entire region of the display device 100 but in a
part of the display device 100 which includes at least the curved
part 120. In this part, the organic film 128 is arranged
continuously in the first surface 10, second surface 20 and a side
surface which intersects both the first surface 10 and second
surface 20. In other words, the organic film 128 is arranged across
the entire periphery of one part of the display device 100
including at least the curved part 120. Since the organic film 128
includes flexibility the same as the first substrate 102, the
organic film 128 has a high resistance to bending and it is
difficult for defects such as cracks to occur. The organic film 128
is also arranged along a curved surface of the first substrate 102
in the curved part 120. As a result, even if defects such as cracks
occur in an insulation layer of the second wiring part 116, such
defects are not exposed to the exterior. In addition, the display
device 100 includes a part (non-curved part) which is different to
the curved part 120 and the non-curved part includes a region in
which the organic film 128 is not formed. That is, it is not the
case that the organic film 128 is arranged continuously in the
entire periphery (that is, all of the first surface 10, second
surface 20 and side surface intersecting both the first surface 10
and second surface 20) of the display device 100.
[0027] Furthermore, by using a cover film with low moisture
permeability (high resistance to gas or high moisture resistance)
as the organic film 128, it is possible to maintain reliability of
the display device 100 even if defects such as cracks occur in the
second wiring part 116. It is desirable that a material which has
excellent non-moisture permeability properties (gas barrier
properties) and mechanical characteristics (resistance to bending)
be used as the organic film 128.
[0028] It is preferred that polychloropyroxyline is used as the
organic film 128 or the organic film 128 contains
polychloropyroxyline. Various types of polychloropyroxyline are
known that have different molecular structures such as parylene C,
parylene N and parylene D. Although any one of parylene C, parylene
N and parylene D may be used as the organic film 128, among these
it is preferred that parylene C is used since it is has the highest
resistance to moisture.
[0029] A polychloropyroxyline thin film as the organic film 128 can
be manufactured using a vacuum deposition method. A
polychloropyroxyline thin film manufactured using a vacuum
deposition method grows at molecular units. As a result, regardless
of the shape of a deposition surface, it is possible to uniformly
form a polychloropyroxyline thin film even in fine gaps. A
polychloropyroxyline thin film can be formed using a vacuum
deposition method with a thickness from a few micrometers to a few
tens of micrometers and it is possible to exhibit sealing
capabilities even at this thickness. Furthermore, when arranging
the organic film 128 in the curved part 12, a shadow mask including
an aperture part corresponding to the curved part 120 of the first
substrate 102 may be used when forming the polychloropyroxyline
thin film. By using a shadow mask when forming a film, it is
possible to selectively grow a polychloropyroxyline thin film in
the curved part 120 without forming the organic film 128 in other
regions such as the pixel part 104.
[0030] In this way, according to one embodiment of the present
invention, it is possible to prevent a drop in reliability due to
defects such as cracks even in the case where a substrate is curved
in a display device using a substrate having flexibility.
[0031] Next, details of the display device 100 related to the
present embodiment are explained while referring to FIG. 5 and FIG.
6. A cross-sectional structure corresponding to the line A-B shown
in FIG. 1 is shown in FIG. 5 and a cross-sectional structure
corresponding to the line C-D is shown in FIG. 6. Furthermore, FIG.
5 shows a state in which the display device 100 is bent by the
curved part 120 and FIG. 6 shows a cross-sectional view of the
curved part 120.
[0032] In the display device 100, the first substrate 102 is curved
by the curved part 120 and the second drive circuit 110 and
terminal part 112 are arranged on the rear surface side (second
surface 20 side) of the pixel part 104. The second wiring part 116
is arranged between the pixel part 104 and the second drive circuit
110. The second wiring part 116 is arranged along a curved surface
of the curved part 120.
[0033] The pixel part 104 is arranged in the first surface 10 of
the first substrate 102. The example shown in FIG. 5 shows a form
in which a transistor 130, light emitting element 132, first
capacitor element 134 and second capacitor element 136 are included
in a pixel 106. The light emitting element 132 is electrically
connected with the transistor 130. The first capacitor element 134
stores a gate voltage of the transistor 130 and the second
capacitor element 136 is additionally arranged in order to adjust
the amount of current flowing to the light emitting element 132.
Furthermore, the pixel 106 shown in FIG. 5 is only an example and a
pixel may be formed by a transistor and a light emitting element or
by a transistor, light emitting element and a first capacitor
element. Alternatively, elements other than a transistor, light
emitting element and first capacitor element may also be added to
form a pixel.
[0034] The transistor 130 includes a structure in which a
semiconductor film 138, gate insulation film 140 and gate electrode
142 are stacked. A source/drain electrode 152 is arranged on an
upper surface of the first insulation film 144. The source/drain
electrode 152 contacts a source region of the semiconductor film
138 or a region corresponding to a drain region for achieving
electrical conduction. A second insulation film 146 is arranged as
a planarized layer above the source/drain electrode 152. In
addition, the light emitting element 132 is arranged above the
second insulation film 146. The first insulation film 144 is formed
using an inorganic insulation material and the second insulation
film 145 is formed using an organic insulation material as the
structure of the pixel 104. The first capacitor element 134 is
formed including a region in which the semiconductor film 138 and a
first capacitor electrode 154 overlap using the gate insulation
film 140 as a conductive film, and a region in which the
source/drain electrode 152 and the first capacitor electrode 154
overlap using the gate insulation film 140 as a conductive film.
The second capacitor element 136 is formed in a region in which the
first electrode 158 and second capacitor electrode 156 overlap
using a third insulation film 148 arranged above the second
insulation film 146 as a conductive film. The third insulation film
148 is formed from an inorganic insulation material such as silicon
oxide, silicon nitride or silicon oxynitride.
[0035] The light emitting element 132 includes a structure in which
the first electrode 158 (pixel electrode) electrically connected
with the transistor 140, light emitting layer 160, and second
electrode 162 (common electrode) are stacked. The light emitting
element 132 controls emitted light by controlling the potential
between the first electrode 158 and second electrode 162. The pixel
part 104 includes a bank layer 164 which covers a periphery edge of
the first electrode 158 and exposes an interior region. The light
emitting layer 160 is arranged across the bank layer 164 from an
upper surface of the first electrode 158. The second electrode 162
covers an upper surface of the light emitting layer 160 and is
arranged across roughly the entire surface of the pixel part
104.
[0036] The light emitting layer 160 is a layer including an organic
electroluminescence material as a light emitting material. The
light emitting layer 160 is formed using a low molecular or high
molecular organic material. In the case where a low molecular
material is used for the light emitting layer 160, in addition to
the light emitting layer which includes an organic material with
light emitting properties, one or a plurality of a hole injection
layer, electron injection layer, hole transport layer and electron
transport layer sandwiching the light emitting layer may also be
included. Since the light emitting layer 160 degrades due to water,
a fourth insulation film 150 is arranged above the second electrode
162. The fourth insulation film 150 is arranged on roughly the
entire surface of the pixel part 104.
[0037] A single layer of or stacked layer body of an inorganic
insulation film such as silicon nitride, silicon oxide or aluminum
oxide is used as the fourth insulation film 150. Furthermore, an
insulation film comprised from a stacked layer body of an organic
insulation film and inorganic insulation film may be arranged above
the fourth insulation film 150. A sealing member 126 is arranged on
an upper surface side of the fourth insulation film 150. FIG. 5
shows the case where the sealing member 126 is a sheet shaped
substrate. In this case, the sealing member 126 is fixed to the
first substrate 102 by a sealing material 172 which encloses the
outer periphery of the pixel part 104. Gaps are present between the
fourth insulation film 150 and sealing member 126 and these gaps
may be filled with a filler material. A resin material is used for
the filler material.
[0038] An aperture part 168 which splits the second insulation film
146 and bank layer 164 is included between an end part (region
contacting the sealing material 172) of the pixel part 104 and a
pixel 106. The third insulation film 148 formed from an inorganic
material and the second electrode 162 are arranged so as to cover a
side surface and bottom surface of the aperture part 168. In other
words, a region is included in which the third insulation film 148
and second electrode 162 contact in the aperture part 168. By
adopting this type of structure, the light emitting layer 160 is
essentially enclosed and sealed by the third insulation film 148
and second electrode 162. That is, by adopting this type of sealing
structure, water and the like is prevented from passing through the
second insulation film 146 which is formed from an organic resin
material and the bank layer 164, and infiltrating the light
emitting layer 160. In addition, the pixel part 104 is arranged
with a connection part 170 in which the second electrode 162 is
electrically connected with lower layer wiring.
[0039] The first substrate 102 is arranged with first wiring 166
from the pixel part 104 to the second drive circuit 110. A region
in which the first wiring 166 is arranged is also a region
corresponding to the curved part 120. For example, the first wiring
166 is formed in the same layer as the source/drain electrode 152.
For example, the first wiring 166 includes a structure in which an
aluminum film (Al) and a metal film with a high melting point such
as titanium (Ti) or molybdenum (Mo) are stacked above and below the
aluminum film. The third insulation film 148 and fourth insulation
film 150 arranged extending from the pixel part 104 are stacked
above the first wiring 166. Although the curved part 120 exists in
a region on the outer side of the sealing member 126, by arranging
the third insulation film 148 and fourth insulation film 150, the
first wiring 166 is protected by these insulation films and is
never exposed directly to the air.
[0040] The organic film 128 is arranged in the curved part 120.
That is, the organic film 128 is arranged in a region on the outer
side of the sealing member 126. The organic film 128 is preferred
to be arranged as the outermost layer in the curved part 120. FIG.
5 includes a structure in which the gate insulation film 140, first
insulation film 144, first wiring 166, third insulation film 148
and fourth insulation film 150 are stacked above the first
substrate 102 in the curved part 120. Furthermore, the organic film
128 is arranged above the fourth insulation film 150.
[0041] When the first substrate 102 is curved, bending stress is
applied to the second wiring part 116. At this time, since the
first wiring 166 is a metal film, it is possible to be deform in
response to bending of the substrate which is flexible. However,
since the third insulation film 148 and fourth insulation film 150
are formed from an inorganic material, when the first substrate 102
is curved, defects such as cracks occur due to brittleness. When
defects such as cracks which occur in these inorganic insulation
films spread towards the pixel part 104, water and the like in the
air infiltrates the pixel part 104 from these defects. For example,
when the first substrate 102 is repeatedly bent by the curved part
120, stress is repeatedly applied to the second wiring part 116 and
thereby defects such as cracks occurring in an inorganic insulation
film grow.
[0042] As described previously, a water blocking structure is
adopted for the display device 100 in which the third insulation
film 148 and second electrode 162 are in close contact in the
aperture part 168. As a result, the display device 100 can to a
certain extent prevent water from infiltrating to the light
emitting layer 160. However, a contact hole which electrically
connects the first electrode 158 and the source/drain electrode
152, and a contact hole which electrically connects the
source/drain electrode 152 and the semiconductor film 138 are
arranged in a pixel 106. These contact holes are formed in the
first insulation film 144 or second insulation film 146. Water and
the like which infiltrates from the exterior to the pixel part 104
can form a path which infiltrates to a region in which the light
emitting layer 160 is arranged via a contact hole which passes
through the first insulation film 144 or second insulation film
146. Due to this, degradation of a light emitting element 132 in
the pixel part 104 occurs after manufacture of the display device
100 which leads to a decrease in display quality.
[0043] However, in the present embodiment, the organic film 128
covers the top of the fourth insulation film 150 in the curved part
120. As a result, it is possible to prevent defective parts from
being exposed to the air even when these defects such as cracks
occur in either the gate insulation film 140, first insulation film
144, third insulation film 148 and fourth insulation film 150 which
are inorganic insulation films.
[0044] Defects such as cracks which occur in the second wiring part
116 also easily occur in an end part of the first substrate 102
where stress is easily concentrated. However, as is shown in FIG.
6, by arranging the organic film 128 to cover the entire periphery
of the first substrate 102, it is possible to ensure that defects
are not exposed to the air even when defects such as cracks occur
in an end part of the first substrate 102.
[0045] In addition, as is shown in FIG. 6, the second wiring 116 is
mixed with a region in which the gate insulation film 140, first
insulation film 144, first wiring 166, third insulation film 148
and fourth insulation film 150 are stacked above the first
substrate 102 from the first substrate 102 side, and a region in
which the gate insulation film 140, first insulation film 144,
third insulation film 148 and fourth insulation film 150 are
stacked. Stress is concentrated in a boundary between these two
regions when the first substrate 102 bends due to a difference in
their stacked structures. For example, it is possible that stress
is concentrated in the third insulation film 148 which covers the
first wiring 166. Even in this case, by arranging the organic film
128 in an outermost layer, it is possible to prevent defective
parts from being exposed to the air even when defects occur in the
third insulation film 148.
[0046] Although a form is shown in the present embodiment in which
the curved part 120 of the display device 100 is arranged in a
region overlapping the second wiring part 116, the present
invention is not limited to this structure. For example, the curved
part 120 may also be arranged to overlap the first wiring substrate
114. In addition, the curved part 120 may also be arranged to
intersect the pixel part 104. In either case, by arranging the
organic film 128 as an outermost layer in the curved part 120 where
the first substrate 102 bends, it is possible to increase
resistance to problems that can occur due to bending of the first
substrate 102.
[0047] Although a form is shown in the present embodiment in which
the light emitting element 132 is arranged in the pixel part 104 as
a display element, the light emitting element can also be applied
to display devices formed with a pixel using other display
elements. For example, the structure shown in the present
embodiment can also be applied to a liquid crystal display device
using liquid crystal elements as a display element.
[0048] Based on the display device described in the embodiments of
the present invention, a person ordinarily skilled in the art could
appropriately perform an addition or removal of structural
components or design modification or an addition of processes or an
omission or change in conditions which are included in the scope of
the present invention as long as they do not depart from the
subject matter of the present invention.
[0049] In addition, other effects that are different from those
provided by the embodiments described above are obvious from the
description in the specification, and effects that could be easily
conceived of by a person ordinarily skilled in the art should be
interpreted as also being provided by the present invention.
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